BSysE 595 Class Projcet
Xin Gao 11212457
BSysE 595 Class Project
Project name
Maximize the yield of Astaxanthin in the Haematococcus pluvialis growth
Project description
Astaxanthin is a carotenoid. It belongs to a larger class of phytochemicals known as terpenes,
which are built from five carbon precursors; isopentenyl diphosphate and dimethylallyl
diphosphate [1]. It is currently used as a feed supplement for seafood and animals [2]. The
primary use for humans is as a food supplement [2], which is a high-value product. Researches
showed that, due to astaxanthin's potent antioxidant activity, it may be beneficial in
cardiovascular, immune, inflammatory and neurodegenerative diseases. Some research
supports the assumption that it may protect body tissues from oxidative and ultraviolet damage
through its suppression of NF-κB activation.
Astaxanthin can be found in microalgae, yeast, salmon, trout, krill, shrimp, crayfish, crustaceans,
and the feathers of some birds [1]. It is difficult to synthetize astaxanthin artificially, because
synthetic astaxanthin always contains a mixture of stereoisomers [3]. Another method is
extracting it from the shellfish [4]. However, this method is limited by the low content of
astaxanthin in the shellfish, also the product yield and purity are not satisfied enough, which
cause the high cost. Some researchers [5] use yeast to product the astaxanthin, such as Phaffia
rhodozyma, Rhodotorula rubra and Rhodotorula glutinis. But, now the highest yield is only 0.3%
of the dry cell weight and small condition changes will easily affect the accumulation of
astaxanthin during the fermentation, such as temperature, pH value, dissolved oxygen, carbon
and nitrogen sources and so on. All in all, these are not the perfect method for this project.
In this project, Haematococcus pluvialis, one kind of the microalgae, was chosen to product the
astaxanthin. Haematococcus pluvialis can produce the astaxanthin as high as 4% of the dry cell
weight [3]. The current limitations are: 1). this kind of microalgae grows slowly, requires longer
time; 2). it is also sensitive to environmental changes and susceptible to other algae, bacteria
and pollutions; 3). the yield of 4% of dry cell weight is not ideal enough. So, it is necessary to
optimize the culture conditions to grow the Haematococcus pluvialis faster and research the
maximum biomass and then improve the product yield by changing the light intensity,
temperature, nutrient, etc.
Objectives
1. Find the optimal environment for growing the Haematococcus pluvialis faster and also it can
reach the maximum biomass.
2. Improve and maximize the product yield of the astaxanthin.
BSysE 595 Class Projcet
Xin Gao 11212457
3. Learn to use the MATLAB COBRA toolbox to calculate the flux balance analysis and analyze
the metabolic engineering.
4. Try to find the optimal model by using the function of the dynamic flux balance analysis.
Research methods
Two main methods and software will be applied in this project, one is minitab for the
mathematic and statistic analysis to find the optimal environment for growing the
Haematococcus pluvialis faster and also reach the maximum biomass, using the ANOVA (analysis
of variance) table based on the actual experimental data. The other one is the MATLAB COBRA
toolbox, this will be used for the calculation of the flux balance analysis and analyze the
metabolic engineering. Also, the optimal model by using the function of the dynamic flux
balance analysis will be tested.
Time line
Task
Timeline
Prepare the Haematococcus pluvialis in the reactors
02/10/2013
Literature review
02/15/2013
Change different culture conditions
03/05/2013
Optimize the culture conditions (ANOVA)
03/20/2013
Calculate the flux balance analysis (COBRA)
04/05/2013
Improve and maximize the product yield (ANOVA)
04/10/2013
Analyze the metabolic engineering (COBRA)
04/26/2013
Establish and find the optimal model (COBRA)
04/30/2013
Project report
05/03/2013
Reference
1. Yousry M. A. Naguib. Antioxidant Activities of Astaxanthin and Related Carotenoids. J. Agric.
Food Chem., 2000, 48 (4), pp 1150–1154.
2. P. Stepnowski, G. Ólafsson, H. Helgason, B. Jastorff. Recovery of astaxanthin from seafood
wastewater utilizing fish scales waste. Chemosphere. 2004, 54(3), pp 413–417.
BSysE 595 Class Projcet
Xin Gao 11212457
3. Makio Kobayashi, Toshihide Kakizono, Shiro Nagai. Astaxanthin production by a green alga,
Haematococcus pluvialis accompanied with morphological changes in acetate media.
Journal of Fermentation and Bioengineering. 1991, 71(5), pp 335–339.
4. W. Miki, K. Yamaguchi, S. Konosu. Comparison of carotenoids in the ovaries of marine fish
and shellfish. Comparative Biochemistry and Physiology Part B: Comparative Biochemistry.
1982, 71(1), pp 7–11.
5. Eric A. Johnson and Michael J. Lewis. Astaxanthin Formation by the Yeast Phaffia rhodozyma.
Microbiology. 1979, 115(1), pp 173-183.